The synthesis of certain morpholinobenzimidazole compounds is described by Nair and Adams in the Journal of the American Chemical Society, Volume 83, pages 3518-3521 (1961). These compounds are prepared by the oxidative cyclization of the corresponding ortho-anilinomorpholine compound with peroxytrifluoroacetic acid according to the following reaction ##STR1## in which X equals hydrogen, chloro, methyl or nitro. The peroxytrifluoroacetic acid is prepared in situ by using trifluoroacetic acid (or anhydride) and 30% hydrogen peroxide. Solvents such as methylene chloride are generally suitable for the reaction. The ortho-anilinomorpholines can be prepared by catalytic or chemical reduction of the corresponding ortho-nitrophenylmorpholine compounds.